mike said he was thinking about （）the maths problem at that time_其他解答

mike said he was thinking about （）the maths problem at that time .
a.which to do b.what to do c.how to do d.why to do选哪个?为什么?

人气：496 ℃　时间：2019-08-28 08:45:00

解答

答案选【C】
宾语从句,翻译如下：
【迈克说他那时候在想怎样做那到数学题】